If your TortoiseSVN client stores an incorrect username or password it will try to access the Subversion server with that stored data. To force TortoiseSVN to ask for a new username and password clear the stored data. TortoiseSVN is a shell extension, so you have to start Windows Explorer to access the TortoiseSVN menu.

Start Windows Explorer,

Right click on any folder and select “TortoiseSVN”, “Settings”,

On the left side of the TortoiseSVN Settings window select “Saved Data”.

On the right side click the Authentication data “Clear” button.

Next time you try to access the Subversion server TortoiseSVN will ask for your user name and password.